The amount of work depends on how far down you plan to disassemble the filter to clean. First of, it is as easy as it shows on the various videos you find on the web, just be careful with the fabric on the grids as to not tear them by brushing up against objects or rocks, etc. If the grids are not too clogged or scaled you may only need to do a spray down of the grids to clean off the DE. If the grids are really clogged and dirty that a spray down does not work, then you will need to do an acid wash. (which I have the pool store or someone else do)
Once you get the top of the filter off on the Pentair, just pull the grids straight up and out of the filter body and place it on a pad, trap or grass. (there are hand hold on top of the filter) Try spraying it off first before thinking of disassembling the grids. If you can the grids to to come cleans (some what white looking) then you are good and can put the filter back in the filter body. Make sure to clean in between the filters to get all the DE out that is clogged in there. A good sprayer nozzle on the hose end will normally do the job. You will probably get wet and covered with DE if not careful.
Once you have cleaned and put the grids back into the tank body, carefully seating the grids on the lower return pipe, you can put the top back on. Clean the tank o-ring and slather it with some silicone and place it back on the lower tank body before placing the top back on.
The first time i did this operation myself, I was nervous also, but found out it was not hard at all. - go for it.
